Direct exchange heat pump with ground probe of iron angled at 25 degrees or less or other material angled at 4 degrees or less to the horizontal

ABSTRACT

Disclosed is a ground probe heat pump system including a direct exchange heat exchanger installed in the earth at a nearly horizontal angle. The ground probe includes separate flow paths for a working fluid allowing the working fluid to directly exchange heat energy with the ground. Also disclosed are methods of installing multiple probes and heat pump systems in various arrangements separately or in conjunction with existing heating and cooling systems. Included are embodiments of the ground probe which are predominantly iron configured to be inserted through a below-ground level structure such as a basement wall by pounding or otherwise applying pressure to the ground probe.

BACKGROUND

Heat pumps are common in homes and commercial settings for both heatingand cooling the air inside a building. Heat pump systems commonly use aworking fluid to move thermal energy along a closed loop by compressingthe working fluid in a gas phase thus raising its temperature andpressure. Excess heat is dissipated condensing the high pressure workingfluid into a somewhat cooler liquid phase. The working fluid is thenallowed to reduce pressure creating a two-phase liquid and gas workingfluid that absorbs energy as it evaporates back into a cooler, lowerpressure, gas. The working fluid is then compressed again and the cycleis repeated.

In many instances, the heat dissipated in condensing the working fluidto a liquid, and the heat absorbed in evaporating the working fluid to agas, are obtained from the air using fans or and air heat exchangerseither inside or outside the building. Heating or cooling can beachieved by selectively controlling the movement of the working fluidthrough a series of valves between the heat exchangers. In hot weather,an outdoor heat exchanger dissipates the heat of condensation into theair while an indoor heat exchanger cools the indoor air absorbing heatas the working fluid evaporates. By reversing the flow and sequence,heating inside the building is achieved using the indoor exchanger as acondenser, and the outdoor exchanger as an evaporator.

However, as the difference between the air temperature and the workingfluid temperature narrows, it becomes more and more difficult totransfer thermal energy. This becomes especially difficult in the wintermonths where the thermal load on the structure is high and the ambientair temperature is very low, perhaps even below 0 degrees Fahrenheit. Asoutdoor temperatures drop below about 35 to 40 degrees Fahrenheit, airsource heat pumps become increasingly less efficient at moving heat. Ifthe air is cold enough, and the thermal load high enough, an air sourceheat pump will not be able to move heat energy into the structure fastenough to replace heat lost to convection, conduction, and radiation.

Ground source or geothermal heat pumps provide one solution to thedifficulties caused by the seasonal swings in the ambient airtemperature. Temperatures below ground near the earth's surface (such aswithin 50 feet) are generally between 50 and 60 degrees in most places,even in northern latitudes. Geothermal systems can be fairly effectiveat using the earth as a heat source for collecting heat energy inwinter, or as a heat sink for absorbing excess heat in summer. Althoughground temperatures fluctuate somewhat with the seasons, the change issmall when compared to the perhaps 50 to 100 degree Fahrenheit seasonalswings in ambient air temperature many air source heat pumps may try toaccommodate.

To create the necessary heat exchange, some geothermal systems circulatea liquid solution such as a water and ethylene glycol mixture throughplastic tubes buried in a continuous loop underground. In a horizontalinstallation, the loop is buried horizontally around 6 to 10 feetunderground, while in a vertical installation, the loop is buried in oneor more bore holes which may be 100 feet deep or more. A heat exchangertransfers heat between the liquid passing through the buried looptransferring heat between the circulating liquid in the loop and theworking fluid in the heating and cooling system. Heat energy isexchanged between the liquid in the loop and the ground, and thenexchanged again between the liquid and the working fluid.

Although relatively effective, such systems require extra energy tooperate because of the extra heat exchange process between the liquidcirculating through the ground loop and the working fluid circulatingthrough the heating and air-conditioning system in the building. Becauseof this extra heat exchange process, the temperature differentialbetween one end of the loop and the other is generally only a fewdegrees thus requiring the ground loop to be hundreds of feet long inorder to achieve sufficient timely thermal transfer with the earth toachieve positive results. Ground loops are therefore typically installedwith plastic pipe to reduce cost even though the rate of thermaltransfer between the fluid and the ground is reduced because of theinsulative nature of plastic, an aspect of the design that requires theloop to be even longer. Because the loop is so long, heavy trenching ordrilling equipment is generally required to install the loops, eithervertically, or horizontally. This installation cost is often the largestportion of installing a geothermal system, particularly in a residentialsetting. Also, because many homes in residential settings are located onsmall lots, the only installation available is a vertical installationwhich can be the most expensive of all requiring multiple deep boreholes to be drilled thus making the investment in a ground source heatpump prohibitively expensive.

Some advantages can be obtained by circulating the working fluid in theground loop in metal tubing instead of a secondary fluid in plastictubing. These systems, often referred to as “direct exchange” systems,increase efficiency by eliminating the heat transfer between the waterand the working fluid. By circulating the working fluid itself, thedirect thermal exchange between the working fluid and the earth occursmore quickly thus increasing efficiency. However, installing directexchange ground loops usually requires drilling bore holes for the loop,and then filling the airspace around the tubing with a grout or othersuitable filler to reduce the opportunity for inefficiencies created byair pockets in the bore holes. Thus the installation of the directexchange loop can also be complex and prohibitively expensive.

SUMMARY

Disclosed is a direct exchange ground probe heat pump system thatincludes a probe inserted into the ground at an angle that is nearlyhorizontal. The probe operates as a ground source heat exchanger withcounter-current flow paths for a working fluid. A first path and aseparate second path are defined within the probe and are coupled to oneanother near a closed end of the probe. The probe is positioned with theclosed end in the earth and the opposite working end projecting out ofthe earth. The working end is coupled to a compressor and another heatexchanger, such as an air heat exchanger, positioned in a building thuscreating a closed loop containing the working fluid. In operation, theworking fluid transfers heat through the walls of the probe to and fromthe earth around the probe. The opposite heat transfer can be initiatedby the other heat exchanger using the compressor to heat and cool abuilding. The ground probe operates as a condenser when the heat pump isoperating in the cooling mode, and as an evaporator when it is operatingin a heating mode.

Various embodiments of the ground probe are also disclosed. In oneexample, an second outer tube constructed predominantly of iron or apredominantly iron alloy such as steel defines the second separate pathwhile a first inner tube positioned within the second outer tube definesthe first path. The first inner tube may optionally be constructed withor covered with, a layer of a less thermally conductive material such asNylon or PVC. In another embodiment, the ground probe includes ametering device in the first path configured for the heating mode.

Also disclosed are methods for installing a predominantly iron probe ata nearly horizontal angle such as 25 degrees or less from horizontal. Apredominantly iron probe is inserted through the below ground wall ofthe structure such as a footing, basement wall, and the like. Thisinsertion can be made by first creating a hole through the structure,and then inserting the second closed end of the ground probe into theearth outside the wall by applying pressure to the first working endsuch as by repeatedly pounding, or tapping the first working end of theprobe. The ground probe is thus forced into the earth minimizing theopportunity for air pockets to form around the probe without the use ofany drilling equipment or filler. Upon insertion, the ground probe isthen coupled to a compressor and another heat exchanger to provideheating or cooling. In one embodiment, the heat pump system is coupledto an existing heating and cooling system while in another, it isinstalled as a separate heating and cooling system.

In another aspect, multiple heat pump systems are disclosed coupled tovarious heating and cooling systems within a building. Variousinstallations are described including a below ground installation in abelow ground room such as a basement where the heat pump and the heatingand cooling system are in the same room. Also disclosed is a belowground installation into a space such as a crawl space where the heatpump and the heating and cooling system are in separate rooms.

Further forms, objects, features, aspects, benefits, advantages, andembodiments of the present invention will become apparent from thedetailed description and drawings provided herewith.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of one embodiment of a nearly horizontalground probe heat pump system.

FIG. 2A is a first cross sectional view of a first embodiment of aground probe for use with the heat pump system of FIG. 1.

FIG. 2B is a second cross sectional view of the embodiment of the groundprobe shown in FIG. 2A.

FIG. 2C is a cross sectional view of a second embodiment of a groundprobe for use with the heat pump system of FIG. 1.

FIG. 3A is a schematic diagram of a first building with the ground probeheat pump system of FIG. 1 installed.

FIG. 3B is a schematic diagram of a second building with the groundprobe heat pump system of FIG. 1 installed.

FIG. 4A is a schematic diagram illustrating an installation of multipleground probe heat pump systems of FIG. 1.

FIG. 4B is a schematic diagram illustrating an alternate installation ofcertain aspects of the ground probe heat pump systems shown in FIG. 4A.

DETAILED DESCRIPTION

For the purpose of promoting an understanding of the principles of theinvention, reference will now be made to the embodiments illustrated inthe drawings, and specific language will be used to describe the same.It will nevertheless be understood that no limitation of the scope ofthe invention is thereby intended. Any alterations and furthermodifications in the described embodiments and any further applicationsof the principles of the invention as described herein are contemplatedas would normally occur to one skilled in the art to which the inventionrelates. One embodiment of the invention is shown in great detail,although it will be apparent to those skilled in the relevant art thatsome features not relevant to the present invention may not be shown forthe sake of clarity.

The reference numerals in the following description have been organizedto aid the reader in quickly identifying the drawings where variouscomponents are first shown. In particular, the drawing in which anelement first appears is typically indicated by the left-most digit(s)in the corresponding reference number. For example, an elementidentified by a “100” series reference numeral will first appear in FIG.1, an element identified by a “200” series reference numeral will firstappear in FIG. 2, and so on. With reference to the Specification,Abstract, and Claims sections herein, it should be noted that thesingular forms “a”, “an”, “the”, and the like include plural referentsunless expressly discussed otherwise. As an illustration, references to“a device” or “the device” include one or more of such devices andequivalents thereof. It should also be noted that elements in thedrawings are represented schematically unless otherwise indicated.Therefore absolute and relative sizes, angles, positioning, and thelike, of elements in the figures may be exaggerated to better illustratevarious aspects of the disclosure.

One embodiment of a nearly horizontal ground probe heat pump system isillustrated in FIG. 1 at 100. A first heat exchanger 110 is coupled to asecond heat exchanger 120 in a closed also including a compressor 130.Compressor 130, first heat exchanger 110, and second heat exchanger 120operate together in either a heating or cooling capacity circulating aworking fluid in a closed loop as described in further detail below.

First heat exchanger 110 is illustrated as vertically mounted on a lowersurface 108 of a duct 115 so that an air flow 114 may pass through it.Heat is either rejected into air flow 114 from first heat exchanger 110raising its temperature, or heat is absorbed from air flow 114 by firstheat exchanger 110 thus reducing its temperature. In order to achievethis heat transfer, first heat exchanger 110 is coupled to a first line116 for carrying the working fluid, first line 116 is coupled to firstexchanger 110 at a upper connection 113. A second line 117 is alsocoupled to heat exchanger 110 at a lower connection 112. A firstmetering device 111 is positioned between lower connection 112 andsecond line 117 and includes a bypass. Metering device 111 is preferablya variable metering device, such as a conventional expansion valve andthe like. In one embodiment, first metering device 111 allows workingfluid passing into first heat exchanger 110 through second line 117 toreduce pressure expanding into a two-phase liquid and vapor combination.On the other hand, working fluid passing out of heat exchanger 110through first metering device 111 into second line 117 can bypass thechange in pressure and maintain its pressure as it moves toward secondheat exchanger 120.

Second line 117 is also coupled to a second metering device 126 whichmay also include a bypass feature. Second metering device 126 may besimilar to first metering device 111 in that it is preferably a variablemetering device, such as a conventional expansion valve and the like.The second metering device 126 is coupled to second heat exchanger 120by a working end coupling 122 at or near first working end 121. Secondmetering device 126 may be configured to operate like metering device111 in that may also be capable of allowing working fluid passing intosecond heat exchanger 120 through second line 117 to reduce in pressureallowing the formation of a two-phase liquid and gas combination. Inthis configuration, second metering device 126 may also includes abypass that allows working fluid passing out of second heat exchanger120 into second line 117 to maintain it's pressure as it moves towardfirst heat exchanger 110 along the closed loop.

As will be shown in FIG. 2C, some embodiments of the second heatexchanger 120 may include a metering device such as a fixed or variableexpansion device within ground probe 124 rather than mounting the deviceto first working end 121. In that case, second line 117 is coupleddirectly to working end coupling 122 and no second metering device 126is coupled outside probe 124 at first working end 121.

Second heat exchanger 120 includes a ground probe 124, examples of whichare illustrated in further detail in FIGS. 2A through 2C and describedbelow. Ground probe 124 is positioned with a first working end 121 and asecond closed end 125, the enclosed end 125 positioned in the earth 142.Ground probe 124 is coupled to first heat exchanger 110 near a firstworking end 121 where second line 117 couples to first working end 121using a working end coupling 122.

As shown in greater detail in FIGS. 2A and 2B, ground probe 124 definesa first path and a separate second path. The two paths are coupled toone another inside ground probe 124 near second closed and 125. Workingfluid circulating through the two paths absorbs heat directly from theearth 142 around ground probe 124 in the heating mode, or rejects heatdirectly from the working fluid into the earth 142 in the cooling mode.The first path exits ground probe 124 at first working end 121 throughworking end coupling 122. The separate second path exits ground probe124 at a second reversing valve coupling 123 which couples the secondpath to a reversing valve 132 through a second compressor line 134.

Reversing valve 132 is coupled to a compressor 130 which includes acompressor body 136, a compressor suction inlet 131 and a compressoroutlet 133. Compressor suction inlet 131, and compressor output 133 arecoupled to reversing valve 132. The reversing valve is also coupled tosecond reversing valve coupling 123 through second compressor line 134.Second compressor line 134 allows working fluid from the separate secondpath to enter and exit ground probe 124 from reversing valve 132. Firstline 116 is also coupled to reversing valve 132 as well at firstreversing valve coupling 135 thus allowing working fluid to enter firstheat exchanger 110 from compressor 130 through reversing valve 132.

In the illustrated embodiment, compressor 130 and ground probe 124 aremounted on a mounting bracket 140 which is secured to a wall 141.Mounting bracket 140 includes a guide 143 which aid in positioningground probe 124 at the proper angle as it is inserted through wall 141.Mounting bracket 140 is positioned on an inside surface 144 of wall 141and configured so that ground probe 124 passes through bracket 140 andwall 141 into the earth 142 which is adjacent an outside surface 145 ofwall 141.

Also illustrated in FIG. 1 is a controller 150 which may also beincluded with ground probe heat pump system 100. Controller 150 may becoupled to compressor 130 using a control line 151. Controller 150 mayinclude various types of controls such as an electronic or mechanicalthermostat, a mechanical switch, or plugging in the power cord to name afew. In the illustrated embodiment, controller 150 includes a thermostatfor activating ground probe heat pump system 100 when temperatures inthe building reach preprogram setpoints. Further detail on these andother aspects are discussed below with respect to FIGS. 3A and 3B.

In operation in the heating mode, reversing valve 132 is configured tocouple compressor suction inlet 131 to second compressor line 134, andcompressor outlet 133 to first line 116. In this configuration, ascompressor 130 operates, it compresses working fluid vapors pulled fromthe second path within ground probe 124 into a relatively high pressuresuperheated vapor passing through first line 116 into first heatexchanger 110. As air flow 114 passes through first heat exchanger 110,heat from the high pressure vapor within first heat exchanger 110 isrejected into air flow 114, and passes through duct 115. As the vaporscool, they condense into a warm, still relatively high pressure liquid.The vertical mounting of heat exchanger 110 allows gravity to aid in thecollection of the condensed liquid working fluid from the lower portionof first heat exchanger 110. However, other embodiments of heatexchanger 110 may be configured with different mountings as well. In anycase, second line 117 carries the warm condensed liquid at relativelyhigh pressure through first metering device 111 utilizing the bypass toavoid any change in pressure until reaching second metering device 126.Upon passing through metering device 126 into ground probe 124, theworking fluid pressure is allowed to decrease substantially causing thewarm high-pressure condensed liquid and second line 117 to expand,reduce pressure, and cool thus separating into a two-phase liquid andgas combination as it passes into the first path within ground probe124.

As described in further detail in FIG. 2, the warm high-pressure workingfluid passes through the first path in ground probe 124 and as ittransitions to the second path, it absorbs heat from the earth 142 toevaporate the liquid phase of the two-phase working fluid. As the liquidphase evaporates to vapor, the vapors are again reintroduced intocompressor suction inlet 131 through second reversing valve coupling 123and second compressor line 134 and the process is repeated. In this way,heat is collected by the working fluid within ground probe 124 andtransferred to first heat exchanger 110 where it is rejected into airflow 114. The working fluid is then recirculated repeatedly tocontinuously transfer heat from the earth 142 to air flow 114 as long asheat pump system 100 is active.

In the cooling mode, reversing valve 132 is configured to couplecompressor suction inlet 131 to first line 116 and compressor output 133to second compressor line 134 thus effectively reversing the flow of theworking fluid with respect to the heating mode. Compressor 130compresses the working fluid vapors drawn from first heat exchanger 110through first line 116. The compressed vapors are introduced into thesecond path within ground probe 124 as a superheated vapor underhigh-pressure. Here ground probe 124 operates as a condenser and thesuperheated vapor rejects heat into the earth 142 around ground probe124. As heat is rejected, the working fluid becomes a warm liquid underhigh-pressure which is then passed along the first path through secondline 117. As the warm condensed liquid passes through second meteringdevice 126, the expansion process is bypassed allowing the liquid tomaintain its relatively high pressure and temperature.

Upon arriving at first metering device 111, the warm high-pressureliquid is allowed to expand within first heat exchanger 110 thuscreating the two-phase liquid and vapor combination within first heatexchanger 110 at a reduced temperature and pressure. Heat from air flow114 passing through first heat exchanger 110 is absorbed as first heatexchanger 110 operates as an evaporator evaporating the liquid phaseinto vapors which are then reintroduced into compressor suction inlet131 through first line 116 and reversing valve 132. Thus in thisconfiguration, second heat exchanger operates as a condenser while firstheat exchanger operates as an evaporator cooling air flow 114 by movingheat from air flow 114 into the earth 142 around ground probe 124.

Examples of working fluids which may be used includechlorodifluoromethane (CHC1F2) commonly referred to by the AmericanSociety of Heating, Refrigerating and Air-conditioning Engineers(ASHRAE) as R-22, mixtures of Butane (C4H10) and Propane (C3H8) oftenreferred to as R-22A, or mixtures of difluoromethane (CH2F2) andpentafluoroethane (CHF2CF3) commonly referred to by the ASHRAEdesignation R-410A, as well as tetrafluoroethane (CH2FCF3) commonlyreferred to by the ASHRAE designation R-134A. Other suitable workingfluids may also be used taking into consideration the pressures andtemperatures at which the working fluid changes phase from a liquid to agas along with the rated working pressures of the first heat exchanger110, second heat exchanger 120, compressor 130, and the lines andfittings coupling these components together in a closed loop asdescribed above.

Further detail of second heat exchanger 120 is provided in FIGS. 2A, 2B,and 2C illustrating two different embodiments while making reference toparts introduced in FIG. 1 as well. FIG. 2A is a cutaway cross sectionof one embodiment of heat exchanger 120 taken along a line DE shown inFIG. 2B. FIG. 2B is conversely a cutaway cross section of the sameembodiment of heat exchanger 120 taken along line BC shown in FIG. 2A.FIG. 2C is cutaway cross-sectional view of a second embodiment of heatexchanger 120 which is similar to FIG. 2A configured preferably for theheating mode. In FIG. 2C, a metering device is positioned within thefirst flow path inside ground probe 124 rather than coupled to firstworking end 121 outside ground probe 124 as shown in FIG. 1.

In the embodiment illustrated in FIG. 2A, ground probe 124 has a secondclosed end 125 and a first working end 121. As discussed above, secondheat exchanger 120 operates as part of a closed loop containing aworking fluid 235. Working fluid 235 may at different times appearwithin second heat exchanger 120 as either a liquid, a gas, or atwo-phase combination of liquid and gas depending on the pressure andtemperature within second heat exchanger 120.

The illustrated embodiment of second heat exchanger 120 facilitates theexchange of heat discussed above between the ground outside ground probe124 and working fluid 235 inside by providing countercurrent flow pathsfor working fluid 235. A first path 210 is defined by a first tube 217positioned within a second tube 225. A separate second path 212 isdefined by second tube 225 and first tube 217 (here shown with anoptional insulative layer 219). Second tube 225 is coupled to secondcompressor line 134 near first working end 121. Second tube 225 may bespaced away from first tube 217 along a major length of second tube 225by one or more standoffs 220. Standoffs 220 are configured to positionfirst tube 217 away from second tube 225 while still allowing workingfluid 235 to transfer from second closed end 125 to second compressorline 134 through second path 212.

Various embodiments of standoffs 220 are envisioned. For example, oneembodiment of standoffs 220 includes one or more helical structureswrapping circumferentially around first tube 217 along a major length ofthe outside surface of first tube 217 and disposed on the inside surfaceof second tube 225. In another example, standoffs 220 comprise ribs orvanes extending parallel to the long axis A of ground probe 124 that areradially offset to allow working fluid 235 to pass from first workingend 121 to second closed end 125. In other embodiments, standoffs 220may be any suitable arrangement of structures spacing first tube 217away from second tube 225 while also defining apertures through whichworking fluid 235 can pass. Some examples include washers, posts,o-rings or other suitable supporting structures circumferentiallypositioned around first tube 217, these structures defining holes orslots through which working fluid 235 may pass. Or in another example,standoffs 220 may be affixed to first tube 217 or to second tube 225 aswell.

Working fluid 235 is therefore free to circulate through ground probe224. In the heating mode, working fluid 235 moves along a first workingfluid flow 211 as a relatively cool low pressure two-phase liquid andvapor combination entering second heat exchanger 120 from second line117. Working fluid 235 moves through first tube 217 along first path 210where the liquid phase pools in a mixing region 214 near second closedend 125 while the gas phase of working fluid 235 continues toward secondcompressor line 134 under suction from compressor 130. In mixing region214, first path 210 couples with second path 212 allowing working fluid235 to continue along separate second path 212. As working fluid 211occupies second path 212, heat exchange occurs, for example, as heatfrom the ground around second heat exchanger 120 causes the liquid phaseof working fluid 235 to evaporate from the liquid phase to a gas. Thesevapors move then along second path 212 in second working fluid flow 211toward second reversing valve coupling 123 between the outside surfaceof first tube 217 (which may include insulative layer 219 as well) andthe inside surface of second tube 225. The vapors are then reintroducedinto compressor suction inlet 131 through second compressor line 134,compressed again, and reintroduced into first heat exchanger 110 and thecycle is repeated.

In the cooling mode, working fluid 235 enters second heat exchanger 120as a relatively hot high pressure vapor arriving from second compressorline 134. The high pressure, high temperature working fluid 235 occupiessecond path 212 between the outside surface of first tube 217 (possiblyincluding insulative layer 219 as well) and the inside surface of secondtube 225. Heat exchange occurs, for example, as working fluid 235 isdisposed against the inside surface of second tube 225 and rejects heatthrough second tube 225 into the ground around second heat exchanger 120thus condensing from a hot vapor to a relatively high pressure warmliquid. The condensed working fluid 235 passes along separate secondpath 212 in a second working fluid flow 213 into mixing region 214. Thecondensed liquid phase of working fluid 235 pools adjacent second closedend 125 distributing along the bottom inside surface of second tube 225.Working fluid 235 also flows through first path 210 following secondworking fluid flow 213 through first tube 217 finally exiting secondheat exchanger 120 as a warm liquid phase at relatively high pressure.Working fluid 235 then continues through the closed loop where itspressure is reduced by first metering device 111 thus absorbing heatfrom air flow 114 via first heat exchanger 110 as described above.

It can be appreciated from the figures discussed thus far that heattransfer between the ground and the working fluid occurs as the portionof the working fluid in the second separate flow path 212 makes thermalcontact with second tube 225. The ground rests against the outsidesurface of second tube 225 while heat is transferred through second tube225 to or from the working fluid 235 disposed along the inside surface.To achieve a rapid heat transfer between working fluid 235 and theearth, second tube 225 may be constructed of any of a number of metalswhich transfer heat quickly such as copper or iron. For example, ironmay be used to provide sufficient strength to facilitate the insertionof ground probe 124 into the ground by tamping or pounding. In thisembodiment, it may be possible to insert ground probe 124 withoutdrilling bore holes which must then be filled to remove air pocketsaround ground probe 124. Second tube 225 may be constructed of a metalthat is predominantly iron, such as a metal containing over 50 percentiron, up to and including metals comprising 100 percent iron includingductile iron, wrought and tempered iron, either hardened or unhardened.Alloys which are predominantly iron which may also be used includevarious forms of steel which are sometimes over 90 percent iron. Sometypes of steel which may be used include high or low carbon steel,stainless steel, galvanized steel, tool steel, and other similar alloysincluding less than about one percent of elements such as manganese,silicon, nickel, titanium, copper, chromium and aluminum to name a few.

Thermal exchange between the working fluid and the earth may be enhancedby inserting ground probe 124 at an angle rather than level with thehorizontal. Examples of this are illustrated in FIGS. 2A and 2C where aground probe including a second heat exchanger 120 is positioned at anearly horizontal angle between about zero and about four degrees fromthe horizontal. Other embodiments may be advantageously positioned atdifferent angles. For example, a predominantly iron ground probe may bepositioned at a nearly horizontal angle between about zero and about 25degrees from horizontal. Other angles are considered as well and may beadvantageous.

Besides adjusting the angle, or perhaps in concert with it, efficiencymay also be improved by increasing or decreasing the level of the oneliquid phase working fluid 235 pooling near second closed end 125. Thismay be achieved by, for example by reducing the size of first tube 217as well as any additional size created by accompanying insulative layer219 if it is present. Similarly, the end of first tube 217 positionedwithin mixing region 214 may be deflected toward the bottom insidesurface of outer tube 225 such as by bending it or by adding anadditional elbow element.

However, as it may be advantageous to increase thermal transfer betweensecond path 212 and the ground, it may also be advantageous to reducethe thermal transfer between first path 210 and second path 212. Asnoted above, first tube 217 therefore may also include an insulativelayer 219 such as a sheath or coating on the outside surface of firsttube 217 as shown in FIG. 2A. In other embodiments, insulative layer 219may also be a lining on the inside surface of first tube 217. Insulativelayer 219 may be constructed of a material such as a polymeric orplastic material like Nylon, polyvinyl chloride (PVC), fiber glass,polyethylene, or polypropylene to name a few examples. In anotherembodiment, first tube 217 FIG. 2A also illustrates a number of spacers227 positioned at intervals between first tube 217 and insulative layer219. Spacers 227, first tube 217, and insulative layer 219 define one ormore voids 230 between spacers 227 along the length of second tube 219.In this embodiment, voids 230 provide additional insulation furtherreducing the rate of thermal transfer between first path 210 and aseparate second path 212. In yet another variation, voids 230 aresubstantially evacuated of air and other gases between first tube 217and insulative layer 219 creating a near vacuum condition within voids230 to further enhance the insulative quality of insulative layer 219.In this configuration, it may be advantageous to insert ground probe 224into the ground at any angle from zero to 90 degrees from horizontal.

FIG. 2A also shows a first path size 222 and a second path size 223. Asillustrated, first path size 222 is smaller than second path size 223.Various ratios of the size of second path 223 in relation to first path222 are envisioned. For example, second path 223 may be one a half, two,or perhaps three inches in size while first path 222 might be one eightto one inch in size. Thus the ratio of the second path size 223 to thefirst path size 222 might vary between 24 to 1 and one and a half toone. Other embodiments are envisioned as well where the ratios may belarger or smaller where it may be advantageous to use an even largersecond path size 223 with an even smaller first path size 222, or asecond path size 223 that is even closer to first path size 222.

FIG. 2B is a cutaway cross-section taken along the line BC in FIG. 2A.First tube 217 is shown within second tube 225, both having asubstantially circular cross-section. Other cross sectional shapes arealso envisioned whereby ground probe 124 may be constructed of tubinghaving a square, ovular, rectangular, or other geometric cross-sections.Similarly, other embodiments of ground probe 124 may be configured as asingle segmented tube defining a first path and a second separate pathusing segments within a single tube rather than a first tube within thesecond tube as shown.

Also shown in FIG. 2B are spacers 227 between insulative layer 219 andfirst tube 217. Similarly, standoffs 220 are illustrated in FIG. 2B as aring positioned circumferentially around first tube 217 and insulativelayer 219. As shown, standoffs 220 define multiple apertures or holesfor allowing working fluid 235 to pass through as discussed above.

FIG. 2C shows another embodiment of a second heat exchanger at 204similar to the embodiment shown in FIG. 2A. However, in FIG. 2C, a firsttube 218 operates as a metering device or expansion valve configured toaccept first working fluid flow 211 in the heating mode. Included withfirst tube 218 is insulative layer 219, here embodied as a sleeve on theoutside of first tube 218. Insulative layer 219 may also be positionedinside first tube 218 as well, or spaced away from first tube 218 asdescribed above.

First path 210 is larger at first working end 121 than at second closedend 125 and reduces in size along the length of first tube 218. In theillustrated embodiment, first tube 218 has one or more narrowing regions224 reducing its size 222 and therefore reducing the pressure of workingfluid 235. As working fluid 235 passes out of path 210 into the couplingregion 214, the pressure of working fluid 235 is reduced and its volumeexpands forming a two-phase liquid and gas combination at a relativelylow pressure and reduced temperature. The liquid phase of working fluid235 pools in mixing region 214 from which it can be evaporated into agas as it is warmed by heat from the earth around the outside of groundprobe 124. Working fluid 235 can then be drawn into compressor 130through second compressor line 134 and the cycle repeated as describedabove.

Illustrated in FIGS. 3A and 3B at 300 and 305 are examples of a groundprobe heating and cooling system 100 installed in a building. Oneexample of a basement installation of a ground probe heat pump system isshown at 300. A nearly horizontal ground probe heat pump system 100illustrated in FIG. 1 is installed in a building 310 which includes atleast one above ground room 317 and at least one below ground room 312such as a basement room. It should be noted that FIG. 3A is a diagramrepresenting any type of building with at least one room below groundlevel, and at least one room above ground. Examples of building 310include a single story home, a multi-story home, a multi-unit buildingsuch as an apartment complex or duplex, a commercial structure such as aoffice building having one or more floors, a warehouse, factory, orshopping center, or an entertainment facility such as a theater orsports arena, to name a few.

Below ground room 312 includes a wall 322 through which ground probe 124is inserted into the earth 142 outside room 312. Heat pump system 100 ismounted to wall 322 on mounting bracket 140 as illustrated in FIG. 1 andoperates as described above. Ground probe 124 is inserted throughbasement wall 322 into the earth 142 at a nearly horizontal angle ofinsertion 316 which may be any angle 25 degrees or less from horizontal,preferably one half to four degrees below horizontal, most preferablyone and a half degrees below horizontal.

As discussed above, the heat pump system 100 includes lines 116 and 117which are here coupled to a first heating and cooling system 313, asecond heating and cooling system 315 or to both systems as furtherillustrated in FIG. 4A. First heating and cooling system 313 includesone or more ducts 115 for carrying heated or cooled air throughoutbuilding 310. In the embodiment shown, controller 150 is coupled toheating system 313 and heat pump system 100 to operate both systems inconcert to adjust the temperature of the air inside building 310.Controller 150 may include various controls for allowing a user to setone or more temperature setpoints for maintaining a given airtemperature within building 310. First heating and cooling system 313may then be controlled by controller 150 to turn on or off, switch fromheating mode to cooling mode, increase or decrease fan speeds, orperform various other functions for adjusting the temperature of the airwithin building 310. Second heating and cooling system 315 may also becoupled to controller 150 in the case where no first heating and coolingsystem 313 is present.

However, in another embodiment illustrated in FIGS. 3A, 3B, and 4A,second heating and cooling system 315 has a separate control line 325coupled to a second controller 327 independent of first controller 150.In this configuration, second heating and cooling system 315 operates asa detached unit from first heating and cooling system 313 and may bepositioned independently with in separate rooms in building 310.Controller 327 may be a thermostat like controller 150, a mechanicalswitch, or any other device suitable for activating and deactivating thepump system 100. As with controller 150, controller 327 may includevarious buttons, dials, switches, or other controls for allowing a userto set one or more temperature setpoints. Second heating and coolingsystem 315 may then be controlled by controller 327 to turn on or off,switch from heating mode to cooling mode, increase or decrease fanspeeds, or perform various other functions for adjusting the temperatureof the air within room 312 for building 310.

Another example of an installed nearly horizontal ground probe heat pumpsystem 100 is shown in FIG. 3B at 305 where building 311 has a crawlspace 320 instead of a below ground room 312. In this configuration,first heating and cooling system 313 and second heating and coolingsystem 315 are not located in the same room with compressor 130 but arecoupled to it by lines 116 and 117. Ground probe 124, is insertedthrough supporting structure 323 into the earth 142. As described abovewith respect to FIG. 3A, first heating and cooling system 313 includesducts 115 carrying conditioned air throughout building 310 while secondheating and cooling system 315 provides a similar function within agiven room separate from first heating and cooling system 313. Forexample, some installations may not include a first heating and coolingsystem 313 with ducts. In this case, building 310 may include multiplesecondary detached heating systems 315 positioned in and around building310 providing heating or cooling in the one or more rooms 317. Forexample, it may be advantageous to install multiple ground probe heatpump systems 100 within crawl space 320 with multiple second heating andcooling systems 315 positioned nearby and above crawl space 320 in room317.

One installation of multiple ground probe heat pump systems 100 is shownat 400 in FIG. 4A making reference to previous FIGS. 1, 3A, and 3B. FIG.4A also illustrates one embodiment of how heat exchangers 110 could bepositioned within first heating and cooling system 313 and secondheating and cooling system 315 to create more than one air flow pathwithin a building. As shown in FIG. 4A, probes 124A through 124D arepositioned through wall 141 such as wall 322 in FIG. 3A, or supportingstructure 323 in FIG. 3B. Wall 141 has the earth 142 adjacent outsidesurface 145 with the inside surface 144 defining a room within abuilding such as building 310 or 311 shown in FIG. 3A or 3Brespectively. Compressors 130A through 130D are coupled to probes 124Athrough 124D respectively as illustrated in FIGS. 1, 2A, 2B and 2C, anddescribed above. Lines 117A through 117D and 116A through 116D arecoupled to first heat exchangers 110A through 110D to complete a closedloop containing a working fluid. Heat exchangers 110A through 110C arepositioned within ducts 115 wherein air flow 114A is created by a mainblower 405. First heat exchangers 110A are arranged to intercept airflow114A and are used in conjunction with the rest of heat pump system 100to heat or cool air flow 114A as discussed above with respect to FIG. 1.In the configuration shown, airflow 114A also passes through main heatexchanger 407 which is also positioned within an air flow 114A and isalso configurable to either heat or cool air flow 114A.

Controller 150 described above is coupled to compressors 130A through130C as well as to first heating and cooling system 313. In thisconfiguration illustrated at 400, compressors 130A through 130C operateas an auxiliary heating system to operate in addition to heat providedby first eating system 313. For example, heat pump systems 100A through100C may be configured to activate, altogether, one by one in stages, orin predefined groups, when the temperature change in the buildingexceeds a first preset high or low temperature threshold. This thresholdmight be set, for example, in controller 150. Controller 150, in thisexample, then activates and deactivates heat pump systems 100 by sendingsignals along control lines 151A through 151B to the respective heatpump systems as necessary to heat or cool the building. If the thermalload on the building causes the temperature to change beyond a secondhigh or low temperature threshold (which may also be set in controller150), the controller 150 can then activate first heating and coolingsystem 313 through control line 151D to operate in the appropriate modeto provide additional heating or cooling as necessary. First heating andcooling system 313, as well as one or more of the heat pump systems 100may then be deactivated accordingly if and when the first high or lowtemperature thresholds are maintained.

FIG. 4A also includes additional detail regarding the installation andoperation of second heating and cooling system 315. As with the heatpump systems 100A through 100C, heat pump system 100D is also configuredwith a probe 124D inserted through wall 141 into the ground 142. Lines117D and 116D couple compressor 130D to first heat exchanger 110Dlocated in an enclosure 410 having a blower 408. Blower 408 creates airflow 114B passing through first heat exchanger 110D which then entersthe building. As shown in FIGS. 3A and 3B, a control line 325 couplessecond heating and cooling system 315 to heat pump system 100D.Controller 327 is located within enclosure 410 and is coupled to heatpump 100D through a control line 325. In this configuration, secondheating and cooling system 315 illustrates an embodiment of a heat pump100D operating as a heating unit with an air flow 114B separate from airflow 114A moving through duct 115. Thus FIG. 4A shows an example ofmultiple heat pump systems (such as three or more) mounted within aroom, either in a duct (115) or in a separate enclosure (410) configuredto heat or cool one or more rooms inside a building such as building 310or 311.

FIG. 4B illustrates at 405 a second embodiment of duct 115 and firstheat exchangers 110A through 110C operating along with heating firstheating and cooling system 313. In the illustrated configuration, ducts115A through 115C contain first heat exchangers 110A through 110C. Eachduct 115 A through 115C also contains an auxiliary blower 406A through406C for directing individual air flows 412A through 412C air throughheat exchangers 110A through 110C on a separate paths from air flow 114Acreated by main blower 405. Flow valves 420A through 420C are positionedto allow air flows 412A through 412C when auxiliary blowers 406A through406C are activated, and to close when they are deactivated to avoidcirculations of air through ducts 115A through 115C when heat pumpsystem 100A through 100C are not active. In this configuration, heatexchanger's 110A through 110C heat individual flows of air positioned torecombine to form a supply air flow 417 which then enters a buildingsuch as building 310 or 311 and into the one or more rooms like room 312or 317. In another embodiment, ducts 115A through 115C are positioned atvarious locations around a building such as 310 or 311 and are notpositioned close to main blower 405 in order to better provide heatingand cooling in particular locations with the building.

Installing heat pump systems 110A through 110D in FIG. 4A can beaccomplished by first making openings in 146A through 146D in wall 141large enough to allow ground probes 124A through 124D to pass through.Then ground probes 124A through 124D may then be aligned at the properinsertion angle 316, and inserted into the earth 142. The insertion maybe performed by, for example, applying pressure to the first working end121 of each ground probe 124A through 124D. In one example, pressure isapplied by repeated hammering, pounding, or tapping with a hammer, maul,or similar device. In this embodiment of the procedure, mounting bracket140, or another similar alignment device having a guide 143 inclined tothe proper insertion angle may be used to aid in maintaining the desiredangle of insertion during installation. Also, the outer surface ofsecond closed end 125 of ground probe 124 may be substantiallyperpendicular to the long axis A of ground probe 124 to aid in theproper alignment of ground probe 124. In this way, ground probe 124 willbe less likely to deviate from the desired angle of insertion 316 as itis inserted into the earth 142. The process is repeated for each groundprobe 124A through 124D.

When ground probes 124A through 124D are inserted, the first working endof each ground probe 124 may be coupled to mounting bracket 140, andmounting bracket 140 secured to wall 141. The rest of heat pump system100 may then be coupled together as discussed above coupling compressor130, first heat exchanger 110, and second heat exchanger 120 together ina closed loop. Working fluid 235 may then be introduced into the closedloop. These steps, and others, are then repeated for each heat pumpsystem 100A through 100D.

1. A nearly horizontal ground probe heat pump, comprising: a first heatexchanger; a compressor; a second heat exchanger including a probehaving a first working end, the probe defining a first path and aseparate second path coupled to one another near a second closed endpositioned in the earth; a working fluid; and a closed loop includingthe first heat exchanger, the compressor and the second heat exchanger,the closed loop containing the working fluid; wherein the probe isinclined from one half to four degrees below horizontal.
 2. The groundprobe heat pump of claim 1, wherein the first path is smaller thansecond path.
 3. The ground probe heat pump of claim 2, wherein a ratioof a second size of the second path to a first size of the first path isbetween about 25 to 1 and about one and a half to one.
 4. The groundprobe heat pump of claim 1, wherein the second path is defined by apredominantly iron tube.
 5. The ground probe heat pump of claim 3,wherein the predominantly iron tube is predominantly steel.
 6. Theground probe heat pump of claim 1, wherein the first path has asubstantially circular cross section.
 7. The ground probe heat pump ofclaim 1, wherein the first path is defined by a first tube, and thesecond path is defined by a second tube and the first tube is positionedwithin the second tube.
 8. The ground probe heat pump of claim 7, whichadditionally includes a standoff to space a major length of the firsttube away from an inside wall of the second tube.
 9. The ground probeheat pump of claim 7, wherein the first tube includes an insulativelayer.
 10. The ground probe heat pump of claim 1, wherein an outersurface of the closed second end is substantially perpendicular to along axis of the probe.
 11. The ground probe heat pump of claim 1,wherein the first working end is in a room of a building.
 12. The groundprobe heat pump of claim 11, wherein the room is a basement room. 13.The ground probe heat pump of claim 11, wherein the room is a crawlspace.
 14. The ground probe heat pump of claim 1, wherein the compressorand the first working end are mounted on a bracket.
 15. The ground probeheat pump of claim 1, wherein the working fluid is any one of R-22,R-22A, R-134A, or R-410A.
 16. A predominantly iron ground probe heatpump, comprising: a first heat exchanger; a compressor; a second heatexchanger including a predominantly iron probe having a first workingend, the probe defining a first path and a separate second path coupledto one another near a second closed end positioned in the earth; aworking fluid; and a closed loop including the first heat exchanger, thecompressor and the second heat exchanger, the closed loop containing theworking fluid; wherein the probe is 25 degrees or less from horizontal.17. The ground probe heat pump of claim 16, wherein the first path issmaller than second path.
 18. The ground probe heat pump of claim 17,wherein a ratio of a second size of the second path to a first size ofthe first path is between about 25 to 1 and about one and a half to one.19. The ground probe heat pump of claim 16, wherein the predominantlyiron probe is predominantly steel.
 20. The ground probe heat pump ofclaim 16, wherein the first path is defined by a first tube, and thesecond path is defined by a second tube, and the first tube ispositioned within the second tube.
 21. The ground probe heat pump ofclaim 20, which additionally includes a standoff to space a major lengthof the first tube away from an inside wall of the second tube.
 22. Theground probe heat pump of claim 20, wherein the first tube includes aninsulative layer.
 23. The ground probe heat pump of claim 16, whereinthe first working end is in a room of a building.
 24. A multiple groundprobe heating and cooling system for a building, comprising: three firstheat exchangers positioned in the building; three compressors; threesecond heat exchangers, each second heat exchanger including a probehaving a first working end, the probe defining a first path and aseparate second path coupled to one another near a second closed endpositioned in the earth; and three separate closed loops including acorresponding first heat exchanger, compressor and second heat exchangerrespectively, the three separate closed loops each containing a workingfluid; wherein the probe is 25 degrees or less from horizontal.
 25. Theground probe heating system of claim 24, wherein the first path isdefined by a predominantly iron tube.
 26. The ground probe heatingsystem of claim 25, wherein the predominantly iron tube is predominantlysteel.
 27. The ground probe heating system of claim 24, wherein thefirst working end is in a room of a building.
 28. The ground probeheating system of claim 27, wherein the room is a basement room.
 29. Theground probe heating system of claim 27, wherein the room is a crawlspace.
 30. The ground probe heating system of claim 27, wherein thethree first heat exchangers are in a second room.
 31. The ground probeheating system of claim 27, wherein one of the first heat exchangers isin the room, and one of the first heat exchangers is in a second room ofthe building.
 32. The ground probe heating system of claim 27, whereinthe three first heat exchangers are in a duct in the room.
 33. Theground probe heating system of claim 24, wherein the compressors and thefirst working ends are mounted on brackets.